A long term evolution (LTE) system supports two working modes: time division duplex (TDD) and frequency division duplex (FDD). In the TDD working mode, uplink communication and downlink communication between a user terminal (UE) and a base station are performed by using different timeslots on a same frequency channel, and uplink data and downlink data are transmitted on different subframes in a same frame. In the TDD working mode, uplink data and downlink data are transmitted on symmetric frequency channels. Therefore, in the LTE system, uplink communication and downlink communication do not interfere with each other.
With the increase in the number of user terminals, demands for communication traffic keep increasing, and spectrum resources become increasingly scarce. Therefore, new technologies emerge continuously to improve utilization of existing spectrum resources. For example, in an LTE-Advanced system (an evolved LTE system), in the TDD working mode, an uplink-downlink resource configuration can be adjusted dynamically or in a semi-static manner according to demands for uplink and downlink services, that is, it is a dynamic TDD working mode. In the FDD working mode, a full-duplex technology is introduced, enabling a user terminal to send uplink data to a base station and receive downlink data from the base station by using a same frequency, so that network throughput of the LTE system is doubled without building a new base station.
The dynamic TDD working mode and the full-duplex working mode of FDD improve spectrum utilization, but also bring a new problem of interference at the same time. For example, in the dynamic TDD working mode, for two neighboring base stations, at a same moment, one may perform scheduling for a user terminal to send uplink data, and the other may perform scheduling to send downlink data to a user terminal. If two user terminals belonging to cells in which different base stations are located are both located at a border between two cells, an uplink signal of one of the user terminals causes interference to a downlink signal of the other user terminal. In the full-duplex working mode of FDD, a base station can randomly perform scheduling for two different user terminals at the same time on a same channel in a cell within coverage of the base station. If one of the user terminals sends uplink data, the other user terminal receives downlink data, and the two user terminals are near each other, the user terminal sending the uplink data causes great interference to the user terminal receiving the downlink data.